It’s been a while since Apple shared an App Store milestone. The news that Apple’s mobile bazaar now sports over 200,000 items came in Steve Jobs’ thoughts on Flash posted on Apple’s website early morning.A part of Jobs’ rambling about why Apple won’t support Flash is an App Store update, tucked away as a side-note:

The 200,000 apps on Apple’s App Store proves that Flash isn’t necessary for tens of thousands of developers to create graphically rich applications, including games.

This data point matters for it shows an accelerating rate of app submissions since the iPad and iPhone OS 4 unveiling, the proof of developers’ support for Apple’s multitouch computer. Here’s the math…

When iPhone OS 4 was previewed at the Town Hall campus in Cupertino, California, on April 8 – exactly three weeks since today – Jobs told the press that users have downloaded “well over four billion apps,” adding that the store carried over 185,000 items. The 15,000 new apps between then and today amounts to an average of 714 submissions a day.

At the iPad unveiling on January 27, Jobs said there were 140,000 items in the store. This translates to 45,000 new submissions in the 72-day period between the iPad and iPhone OS 4 events, or an average of 625 daily arrivals. In other words, the average rate of daily submissions grew almost 15 percent following the iPad and iPhone OS 4 unveiling.

The acceleration is partially the result of a recent App Store expansion into 13 new countries. Another interesting finding: Four billion downloads spread over 80 million iPhone OS devices (50 million iPhones and 30 million iPod touches) amounts to an average of fifty downloads per user in less than twenty months since the App Store launched, or nearly three app downloads per user each month. Apple announced on January 5 that a user downloaded three billionth app. Note that those download counts excludes software updates.

A January Gartner report suggested that Apple controls a whopping 99.4 percent of the mobile apps market. It had been reported that nobody at Apple had any idea that the App Store would become this huge. Apple’s annual developers conference that will run this year between June 7-11 will shed more light on Apple’s mobile plans. The company wrote in the invitation that “these five days will change how the world does all kinds of things,” telling developers that attending the conference is a “once-in-a-lifetime opportunity” for them and their apps.